Hydraulic system of aerial work platform and aerial work platform

Abstract

The utility model belongs to the technical field of aerial work platforms, and discloses a hydraulic system of an aerial work platform and the aerial work platform. The hydraulic system of the aerial work platform comprises an oil tank, a power device, a main control valve, a flow valve, a floating control valve and a brake releasing control valve. An oil inlet of the power device is communicated with the oil tank, an oil inlet of the main control valve is communicated with an oil outlet of the power device, an oil return opening of the main control valve is communicated with the oil tank, a first oil opening of the flow valve is communicated with a working oil opening of the main control valve, and an oil inlet of the floating control valve and an oil inlet of the brake releasing control valve are communicated with a second oil opening of the flow valve. An oil return opening of the floating control valve and an oil return opening of the brake releasing control valve are communicated with the oil tank, a working oil opening of the floating control valve is communicated with the floating executing mechanism, and a working oil opening of the brake releasing control valve is communicated with the brake releasing executing mechanism. The hydraulic system of the aerial work platform is stable in hydraulic oil flow and can not be affected by loads, the safety of the whole machine is improved, extra hydraulic oil loss is avoided, and more energy is saved.

Description

Technical Field

[0001] The utility model relates to the technical field of aerial work platforms, in particular to a hydraulic system of an aerial work platform and the aerial work platform. Background Art

[0002] Aerial work platforms are widely used in infrastructure, transportation, prefabricated buildings and other aspects. They can generally perform actions such as leg extension and retraction, lifting, steering, floating or brake release. In the prior art, when the aerial work platform performs a floating action, the floating control valve is energized, and the power unit directly delivers the hydraulic oil in the oil tank to the floating actuator through the floating control valve to achieve the floating function; when the aerial work platform performs a brake release action, the brake release control valve is energized, and the power unit directly delivers the hydraulic oil in the oil tank to the brake release actuator through the brake release control valve to complete the brake release function. In the above structure, when the aerial work platform performs the floating function or the brake release function, the hydraulic oil delivered by the power unit is easily affected by the load, which can easily cause oil loss, which is not conducive to energy conservation and emission reduction. Utility Model Content

[0003] The purpose of the utility model is to provide a hydraulic system for an aerial work platform and an aerial work platform, so that the flow rate of hydraulic oil delivered by a power device is stable and not affected by the load, which is conducive to energy conservation and emission reduction.

[0004] To achieve this purpose, the present invention adopts the following technical solutions:

[0005] The hydraulic system of the aerial work platform, including the oil tank, power unit, main control valve, flow valve, and float control valve and / or brake release control valve;

[0006] In which, the oil inlet of the power unit is connected to the oil tank, the oil inlet of the main control valve is connected to the oil outlet of the power unit, the oil return port of the main control valve is connected to the oil tank, the first oil port of the flow valve is connected to the working oil port of the main control valve, the oil inlet of the floating control valve and / or the brake release control valve is connected to the second oil port of the flow valve, the oil return port of the floating control valve and / or the brake release control valve is connected to the oil tank, the working oil port of the floating control valve is connected to the floating actuator and / or the working oil port of the brake release control valve is connected to the brake release actuator.

[0007] As an optional solution, the floating control valve includes a first floating control valve and a second floating control valve, and the floating actuator includes a first floating actuator and a second floating actuator. The oil inlet of the first floating control valve and the oil inlet of the second floating control valve are both connected to the second oil port of the flow valve, the working oil port of the first floating control valve is connected to the first floating actuator, and the working oil port of the second floating control valve is connected to the second floating actuator.

[0008] As an optional solution, the working oil port of the brake release control valve is also connected to an accumulator and a pressure sensor.

[0009] As an optional solution, the hydraulic system of the aerial work platform also includes a leg control valve, the oil inlet of the leg control valve is connected to the oil outlet of the power unit, the oil return port of the leg control valve is connected to the oil tank, the first working oil port of the leg control valve is connected to the rod chamber of the leg group actuator cylinder, and the second working oil port of the leg control valve is connected to the rodless chamber of the leg group actuator cylinder.

[0010] As an optional solution, the hydraulic system of the aerial work platform also includes a shuttle valve and a second relief valve, the first working oil port of the outrigger control valve and the second working oil port of the outrigger control valve are also connected to the first oil inlet of the shuttle valve and the second oil inlet of the shuttle valve respectively, the oil outlet of the shuttle valve is connected to the first oil port of the second relief valve, and the second oil port of the second relief valve is connected to the oil tank.

[0011] As an optional solution, the hydraulic system of the aerial work platform further includes:

[0012] a lift control valve, wherein an oil inlet of the lift control valve is connected to an oil outlet of the power unit, an oil return port of the lift control valve is connected to the oil tank, a second working oil port of the lift control valve is connected to a lift actuator, and when the lift control valve is in a neutral position, the second working oil port of the lift control valve is connected to the oil return port of the lift control valve;

[0013] A steering control valve, the oil inlet of the steering control valve is connected to the first working oil port of the lifting control valve, the oil return port of the steering control valve is connected to the oil tank, the first working oil port of the steering control valve is connected to the rodless chamber of the steering actuator, the second working oil port of the steering control valve is connected to the rod chamber of the steering actuator, and when the lifting control valve is in the middle position, the first working oil port of the lifting control valve is connected to the oil return port of the lifting control valve.

[0014] As an optional solution, the hydraulic system of the aerial work platform also includes a first overflow valve, the first oil port of the first overflow valve is connected to the first working oil port of the lifting control valve and the oil inlet of the steering control valve, and the second oil port of the first overflow valve is connected to the oil tank.

[0015] As an optional solution, the hydraulic system of the aerial work platform also includes a one-way valve, which is arranged on the pipeline between the oil outlet of the power unit and the oil inlet of the main control valve, and the one-way valve is configured to conduct oil in a one-way direction from the power unit to the main control valve.

[0016] As an optional solution, the hydraulic system of the aerial work platform also includes a main overflow valve, the first oil port of the main overflow valve is connected to the pipeline between the oil outlet of the power unit and the oil inlet of the main control valve, and the second oil port of the main overflow valve is connected to the oil tank.

[0017] An aerial work platform comprises the hydraulic system of the aerial work platform described in any of the above solutions.

[0018] Beneficial effects of the utility model:

[0019] The utility model provides a hydraulic system for an aerial work platform. By arranging a flow valve after a main control valve, it is possible to ensure that the flow of hydraulic oil delivered by a power unit to a floating actuator or a brake release actuator is stable and the required flow is provided, thereby ensuring the execution speed of the floating function or the brake release function is not affected by the load, and continuously providing stable hydraulic oil for the floating actuator or the brake release actuator; and when executing the floating function, it is possible to ensure that the tires of the aerial work platform are always in contact with the ground during the driving process, thereby improving the safety of the entire machine; in addition, when the aerial work platform does not need to execute the floating function or the brake release function, there will be no additional hydraulic oil loss, which is more energy-efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the hydraulic system of the aerial work platform provided in an embodiment of the present utility model.

[0021] In the picture:

[0022] 1. Fuel tank; 2. Power unit; 21. Power source; 22. Gear pump; 3. Lift control valve; 4. Steering control valve; 5. First relief valve; 6. Outrigger control valve; 7. Shuttle valve; 8. Second relief valve; 9. First floating control valve; 10. Second floating control valve; 20. Brake release control valve; 30. Main control valve; 40. Flow valve; 50. Check valve; 60. Main relief valve; 70. Pressure reducing valve; 80. Accumulator. DETAILED DESCRIPTION

[0023] The following describes in detail embodiments of the present invention. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar components or components having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present invention, and should not be construed as limiting the present invention.

[0024] In the description of this utility model, unless otherwise expressly specified or limited, the terms "connected," "connect," and "fixed" should be understood in a broad sense. For example, they may refer to fixed or detachable connections, mechanical or electrical connections, direct or indirect connections through an intermediate medium, and internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in this utility model based on specific circumstances.

[0025] In the description of the present utility model, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may include the first feature and the second feature being in direct contact, or may include the first feature and the second feature being in contact not directly but through another feature between them. Moreover, a first feature being "above," "above," and "above" a second feature includes the first feature being directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below," "below," and "below" a second feature includes the first feature being directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0026] The technical solution of the present invention will be further described below with reference to the accompanying drawings and through specific implementation methods.

[0027] like Figure 1 As shown, an embodiment of the present invention provides a hydraulic system for an aerial work platform, which includes an oil tank 1, a power unit 2, a main control valve 30, a flow valve 40, a floating control valve and a brake release control valve 20.

[0028] Among them, the oil inlet of the power unit 2 is connected to the oil tank 1, the oil inlet of the main control valve 30 is connected to the oil outlet of the power unit 2, the oil return port of the main control valve 30 is connected to the oil tank 1, the first oil port of the flow valve 40 is connected to the working oil port of the main control valve 30, the oil inlet of the float control valve and the brake release control valve 20 is connected to the second oil port of the flow valve 40, the oil return port of the float control valve and the brake release control valve 20 is connected to the oil tank 1, the working oil port of the float control valve is connected to the floating actuator, and the working oil port of the brake release control valve 20 is connected to the brake release actuator. When performing a floating action, the power unit 2 passes the hydraulic oil in the oil tank 1 through the main control valve 30 and the flow valve 40 and then through the float control valve into the floating actuator to achieve the floating function; when performing a brake release action, the power unit 2 passes the hydraulic oil in the oil tank 1 through the main control valve 30 and the flow valve 40 and then through the brake release control valve 20 into the brake release actuator to achieve the brake release function.

[0029] By installing a flow valve 40 after the main control valve 30, the hydraulic system of this aerial work platform ensures a stable and required flow of hydraulic oil from the power unit 2 to the floating actuator or brake release actuator. This ensures the execution speed of the floating or brake release functions is unaffected by the load and continuously provides a stable supply of hydraulic oil to the floating actuator or brake release actuator. Furthermore, when the floating function is in operation, the tires of the aerial work platform are kept in contact with the ground, enhancing the safety of the entire machine. Furthermore, when the aerial work platform does not need to perform the floating or brake release functions, there is no additional hydraulic oil loss, which is more energy-efficient.

[0030] Of course, the hydraulic system of the aerial work platform can also have only floating function or brake release function according to needs.

[0031] Optionally, the power device 2 includes a power source 21 and a gear pump 22 . The power source 21 can be a motor or an engine. The power source 21 provides mechanical energy to the gear pump 22 . The oil inlet of the gear pump 22 is connected to the oil tank 1 .

[0032] The floating control valve has a first working position and a second working position. When the floating function does not need to be performed, the floating control valve is in the first working position, and the working oil port of the floating control valve is connected to the return oil port of the floating control valve; when the floating function needs to be performed, the floating control valve is in the second working position, and the oil inlet of the floating control valve is connected to the working oil port of the floating control valve, so that the gear pump 22 delivers the hydraulic oil in the oil tank 1 to the floating actuator through the floating control valve.

[0033] The working oil port of the brake release control valve 20 is also connected to the accumulator 80 and the pressure sensor respectively, that is, the working oil port of the brake release control valve 20 is connected in parallel to the BR port, the AC port and the PS port, which are respectively used to connect the brake release actuator, the accumulator 80 and the pressure sensor. The brake release control valve 20 has a first working position and a second working position. When the aerial work platform is moving and the pressure sensor detects that the pressure is lower than the lowest value of the set pressure range, the brake release control valve 20 is in the second working position, and the working oil port of the brake release control valve 20 is connected to the oil inlet of the brake release control valve 20, so that the power source 21 drives the gear pump 2 2. Hydraulic oil in the fuel tank 1 is delivered to the AC port through the brake release control valve 20, where it enters the accumulator 80 for filling. When the pressure sensor detects a pressure higher than the maximum value in the set pressure range, the brake release control valve 20 enters the first working position, the working oil port of the brake release control valve 20 is connected to the return oil port of the brake release control valve 20, the power source 21 stops, and no further filling of the accumulator 80 is performed to save energy. However, when the brake release function is required, the accumulator 80 provides hydraulic oil to the brake release actuator. Accumulator 80 acts as an energy storage device, preventing the power source 21 from rotating continuously during driving and improving driving range. Furthermore, when driving stops, the hydraulic oil in the accumulator 80 flows back to the fuel tank 1 through the brake release control valve 20 to prevent misoperation.

[0034] Optionally, the floating control valve includes a first floating control valve 9 and a second floating control valve 10, and the floating actuator includes a first floating actuator and a second floating actuator. The oil inlet of the first floating control valve 9 and the oil inlet of the second floating control valve 10 are both connected to the oil outlet of the gear pump 22, the oil return port of the first floating control valve 9 and the oil return port of the second floating control valve 10 are both connected to the oil tank 1, the working oil port of the first floating control valve 9 is connected to the first floating actuator, and the working oil port of the second floating control valve 10 is connected to the second floating actuator. The main control valve 30 has a first working position and a second working position. When the floating function and the brake release function are not required, the main control valve 30 is located in the first working position, and the working oil port of the main control valve 30 is connected to the return oil port of the main control valve 30; when the floating function needs to be performed, the main control valve 30, the first floating control valve 9 and the second floating control valve 10 are all energized and switched to the second working position, the power source 21 drives the gear pump 22 to work, and the gear pump 22 delivers the hydraulic oil in the oil tank 1 to the P port, and outputs it to the OL port and the OR port through the main control valve 30, the flow valve 40, the first floating control valve 9 and the second floating control valve 10, respectively, to flow to the first floating actuator and the second floating actuator, completing the floating action.

[0035] Optionally, the hydraulic system of the aerial work platform also includes a pressure reducing valve 70, which is arranged on a pipeline connecting the oil inlet of the brake release control valve 20 and the second oil port of the flow valve 40. By setting the pressure reducing valve 70, the pressure delivered to the BR port can be set within a certain range. For example: the pressure of the pressure reducing valve 70 is set to 3MPa. In the process of the hydraulic oil flowing through the pressure reducing valve and being delivered to the BR port, when the pressure of the working oil port of the main control valve 30 is lower than 3MPa, the working pressure of the BR port is the actual pressure of the working oil port of the main control valve 30. When the pressure of the working oil port of the main control valve 30 is higher than 3MPa, the working pressure of the BR port is 3MPa.

[0036] It can be understood that the set pressure of the pressure reducing valve 70 is greater than the highest value of the set pressure range.

[0037] The hydraulic system of the aerial work platform also includes an outrigger control valve 6, the oil inlet of the outrigger control valve 6 is connected to the oil outlet of the gear pump 22 of the power unit 2, the oil return port of the outrigger control valve 6 is connected to the oil tank 1, the first working oil port of the outrigger control valve 6 is connected to the rod chamber of the outrigger group execution cylinder, and the second working oil port of the outrigger control valve 6 is connected to the rodless chamber of the outrigger group execution cylinder. By setting the outrigger control valve 6, the outrigger group execution cylinder can be controlled individually.

[0038] Furthermore, the outrigger group actuator cylinders include two outrigger actuator cylinders. The first working oil port of the outrigger control valve 6 is divided into two pipelines, each connected to the rod chamber of the two outrigger actuator cylinders, to control the movement of the two outrigger actuator cylinders and achieve the retraction of the two outriggers. The second working oil port of the outrigger control valve 6 is divided into two pipelines, each connected to the rodless chamber of the two outrigger actuator cylinders, to control the movement of the two outrigger actuator cylinders and achieve the extension of the two outriggers. This structure can realize the simultaneous movement of multiple outriggers. Of course, the outrigger group actuator cylinders can also include more than two outrigger actuator cylinders.

[0039] Optionally, the hydraulic system of the aerial work platform further includes a shuttle valve 7 and a second relief valve 8. The first and second working oil ports of the outrigger control valve 6 are further connected to the first and second oil inlets of the shuttle valve 7, respectively. The oil outlet of the shuttle valve 7 is connected to the first oil port of the second relief valve 8, and the second oil port of the second relief valve 8 is connected to the fuel tank 1. For example, when controlling the extension of the outrigger actuator cylinder, the right position of the outrigger control valve 6 is energized, and the power source 21 drives the gear pump 22 to pump hydraulic oil from the fuel tank 1 to port P. After passing through the outrigger control valve 6, some of the hydraulic oil flows through the second oil port of the shuttle valve 7 to the second relief valve 8, while the remaining hydraulic oil flows to ports RF and RR and enters the rodless chamber of the outrigger actuator cylinder, causing the outrigger actuator cylinder to extend, completing the outrigger extension action. At this time, the hydraulic oil in the rod chamber of the outrigger actuator cylinder flows through ports EF and ER, passes through the outrigger control valve 6, and returns to the fuel tank 1 through port T. In this structure, a shuttle valve 7 and a second relief valve 8 are provided. When the pressure of the hydraulic oil is lower than the set pressure of the second relief valve 8, the second relief valve 8 is in a closed state. When the pressure of the hydraulic oil is higher than the set pressure of the second relief valve 8, the second relief valve 8 is passively opened, and the hydraulic oil flows back to the oil tank 1, so that the pressure is limited to the set pressure range, ensuring the safety of the oil circuit; and the second relief valve 8 limits the maximum pressure of the outrigger actuator, that is, the pressure that meets the outrigger movement requirements, and does not cause waste due to excessive pressure, thereby improving the endurance of the entire machine.

[0040] When the outrigger execution cylinder is controlled to retract, the left position of the outrigger control valve 6 is energized, and the hydraulic oil enters the rod chamber of the outrigger execution cylinder through the EF port and the ER port. The hydraulic oil in the rodless chamber of the outrigger execution cylinder flows to the outrigger control valve 6 through the RF port and the RR port and returns to the oil tank 1 through the T port, completing the outrigger retraction action.

[0041] The hydraulic system of the aerial work platform also includes a lift control valve 3. The oil inlet of lift control valve 3 is connected to the oil outlet of gear pump 22. The oil return port of lift control valve 3 is connected to fuel tank 1. The second working oil port of lift control valve 3 is connected to the lift actuator. When a lifting action is performed, lift control valve 3 is energized in the right position, and power source 21 drives gear pump 22 to output hydraulic oil from fuel tank 1 to port P. The oil is then output through lift control valve 3 to port L, and then delivered to the lift actuator through port L, completing the lifting action. Furthermore, when lift control valve 3 is in the neutral position, the second working oil port of lift control valve 3 is connected to the oil return port of lift control valve 3. When the lifting action is completed, lift control valve 3 is in the neutral position, port L is connected to fuel tank 1, and the hydraulic oil in the lift actuator can flow through lift control valve 3 and return to fuel tank 1 through port T to relieve pressure.

[0042] The hydraulic system of the aerial work platform also includes a steering control valve 4. The oil inlet of the steering control valve 4 is connected to the first working oil port of the lift control valve 3. The oil return port of the steering control valve 4 is connected to the fuel tank 1. The first working oil port of the steering control valve 4 is connected to the rodless chamber of the steering actuator, and the second working oil port of the steering control valve 4 is connected to the rod chamber of the steering actuator. When a steering action is executed (e.g., a left turn), the left position of the lift control valve 3 and the left position of the steering control valve 4 are energized. The power source 21 drives the gear pump 22 to output hydraulic oil from the fuel tank 1 to port P. The hydraulic oil is then output through the lift control valve 3 and the steering control valve 4 to port S1. From there, the hydraulic oil is delivered to the rodless chamber of the steering actuator, completing the left turn. When a right turn is executed, the left position of the lift control valve 3 and the right position of the steering control valve 4 are energized. The hydraulic oil is then delivered to the rod chamber of the steering actuator through port S2, completing the right turn. Furthermore, when the lift control valve 3 is in the middle position, the first working oil port of the lift control valve 3 and the return oil port of the lift control valve 3 are connected. That is, assuming that after the left steering action is completed, the lift control valve 3 is first controlled to switch to the middle position. At this time, the S1 port is connected to the oil tank 1, and the hydraulic oil in the rodless chamber of the steering actuator passes through the steering control valve 4 and the lift control valve 3 and flows back to the oil tank 1 through the T port to relieve pressure.

[0043] When the lifting control valve 3 in the hydraulic system of the aerial work platform is in the middle position, the first working oil port of the lifting control valve 3 and the second working oil port of the lifting control valve 3 are both connected to the return oil port of the lifting control valve 3, and the oil inlet of the steering control valve 4 is connected to the first working oil port of the lifting control valve 3, so that the lifting control valve 3 and the steering control valve 4 cooperate to complete the action of the steering actuator and avoid pressure buildup in the steering actuator, and the lifting control valve 3 can complete the action of the lifting actuator alone and avoid pressure buildup, effectively avoiding the problem of misoperation caused by pressure shock and long-term pressure buildup.

[0044] If the lifting actuator needs to return oil, an external oil return control valve can be connected to the oil tank 1. If oil return is not required, the lifting action can be completed.

[0045] Optionally, the hydraulic system of the aerial work platform also includes a first relief valve 5, the first oil port of the first relief valve 5 is connected to the first working oil port of the lifting control valve 3 and the oil inlet of the steering control valve 4, and the second oil port of the first relief valve 5 is connected to the oil tank 1. The first relief valve 5 can set the pressure. When performing a steering action, if the pressure of the oil inlet of the steering control valve 4 exceeds the pressure set by the first relief valve 5, the hydraulic oil will flow back to the oil tank 1 through the first relief valve 5. The first relief valve 5 can set the pressure of the S1 port and the S2 port separately, effectively reducing energy loss and improving the endurance of the aerial work platform. The pressure setting of the first relief valve 5 can be set according to the actual use of different models, and it is sufficient to meet the steering action. Under the premise of achieving the steering action, the setting of its maximum pressure does not affect other actions such as lifting.

[0046] The hydraulic system of the aerial work platform also includes a one-way valve 50, which is disposed at the oil outlet of the gear pump 22 and located in the oil circuit before the oil inlet of the lift control valve 3, the oil inlet of the outrigger control valve 6, and the oil inlet of the main control valve 30. The one-way valve 50 is configured to conduct hydraulic oil in one direction from the gear pump 22 to the lift control valve 3, from the gear pump 22 to the outrigger control valve 6, and from the gear pump 22 to the main control valve 30. The provision of the one-way valve 50 prevents hydraulic oil from flowing back into the gear pump 22, thereby preventing the gear pump 22 from reversing and driving the power source 21 to rotate, thereby reducing the probability of failure of the power source 21.

[0047] The hydraulic system of the aerial work platform also includes a main relief valve 60. A first port of main relief valve 60 connects to the oil outlet of gear pump 22, the oil inlet of lift control valve 3, the outrigger control valve 6, and the main control valve 30. A second port of main relief valve 60 connects to fuel tank 1. Main relief valve 60 allows pressure relief when the total pressure in the hydraulic system of the aerial work platform exceeds the set pressure of main relief valve 60. This limits the maximum pressure of the entire hydraulic system, prevents damage to components due to excessive pressure, and increases their service life.

[0048] The hydraulic system of the aerial work platform can be applied to different models, such as scissor-type aerial work platforms, off-road aerial work platforms, crawler-type aerial work platforms, etc. It can complete outrigger, lifting, steering, floating, brake release and other tasks, and can also be flexibly matched and combined according to needs. For example, if outrigger action is not required, the outrigger control valve 6 can be removed. For example, if floating action is not required, the floating control valve can be removed. Each action is independent of each other and can be freely combined, with high flexibility. Some functions can also be processed separately as optional modules to suit different working conditions.

[0049] In this embodiment, the operator can output signals by operating the lower control box or the control handle to complete actions such as outrigger, lifting, steering, floating or releasing the brake.

[0050] In this embodiment, the power source 21 is selected as an electric motor, which can achieve stepless speed regulation. By controlling the speed of the motor, the speed of each action can be controlled separately, reducing additional energy loss; and the acceleration of the motor can be controlled to achieve a smooth start of each action, avoiding action shock and improving smoothness; in addition, when each action is completed, the motor can be controlled to stop first, and then the solenoid valves such as the lift control valve 3 and the outrigger control valve 6 can be controlled to delay power off to avoid pressure shock caused by pressure buildup in the pipeline.

[0051] Optionally, the lifting control valve 3 , the steering control valve 4 and the outrigger control valve 6 are all three-position four-way valves, and use a valve core with a sliding valve structure, which is highly efficient and low-cost.

[0052] Optionally, the main control valve 30 , the floating control valve and the brake release control valve 20 are all two-position three-way valves.

[0053] An embodiment of the present utility model further provides an aerial work platform, comprising the hydraulic system of the above-mentioned aerial work platform.

[0054] Obviously, the above embodiments of the present invention are merely examples for the purpose of clearly illustrating the present invention, and are not intended to limit the implementation methods of the present invention. Those skilled in the art will appreciate that other variations or modifications can be made based on the above description. It is not necessary and impossible to enumerate all implementation methods here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the claims of the present invention.

Claims

1. The hydraulic system of the aerial work platform is characterized by: It comprises an oil tank (1), a power unit (2), a main control valve (30), a flow valve (40), and a floating control valve and / or a brake release control valve (20); The oil inlet of the power device (2) is connected to the oil tank (1), the oil inlet of the main control valve (30) is connected to the oil outlet of the power device (2), the oil return port of the main control valve (30) is connected to the oil tank (1), the first oil port of the flow valve (40) is connected to the working oil port of the main control valve (30), the oil inlet of the floating control valve and / or the brake release control valve (20) is connected to the second oil port of the flow valve (40), the oil return port of the floating control valve and / or the brake release control valve (20) is connected to the oil tank (1), the working oil port of the floating control valve is connected to the floating actuator and / or the working oil port of the brake release control valve (20) is connected to the brake release actuator.

2. The hydraulic system of the aerial work platform according to claim 1, characterized in that: The floating control valve includes a first floating control valve (9) and a second floating control valve (10), and the floating actuator includes a first floating actuator and a second floating actuator. The oil inlet of the first floating control valve (9) and the oil inlet of the second floating control valve (10) are both connected to the second oil port of the flow valve (40), the working oil port of the first floating control valve (9) is connected to the first floating actuator, and the working oil port of the second floating control valve (10) is connected to the second floating actuator.

3. The hydraulic system of the aerial work platform according to claim 1, characterized in that: The working oil port of the brake release control valve (20) is also communicated with the accumulator (80) and the pressure sensor.

4. The hydraulic system of the aerial work platform according to claim 1, characterized in that: It also includes an outrigger control valve (6), the oil inlet of the outrigger control valve (6) is connected to the oil outlet of the power unit (2), the oil return port of the outrigger control valve (6) is connected to the oil tank (1), the first working oil port of the outrigger control valve (6) is connected to the rod chamber of the outrigger group execution cylinder, and the second working oil port of the outrigger control valve (6) is connected to the rodless chamber of the outrigger group execution cylinder.

5. The hydraulic system for an aerial work platform according to claim 4, characterized in that: It also includes a shuttle valve (7) and a second relief valve (8); the first working oil port of the outrigger control valve (6) and the second working oil port of the outrigger control valve (6) are respectively connected to the first oil inlet of the shuttle valve (7) and the second oil inlet of the shuttle valve (7); the oil outlet of the shuttle valve (7) is connected to the first oil port of the second relief valve (8); and the second oil port of the second relief valve (8) is connected to the oil tank (1).

6. The hydraulic system for an aerial work platform according to claim 1, characterized in that: Also includes: A lifting control valve (3), wherein the oil inlet of the lifting control valve (3) is communicated with the oil outlet of the power unit (2), the oil return port of the lifting control valve (3) is communicated with the oil tank (1), the second working oil port of the lifting control valve (3) is communicated with the lifting actuator, and when the lifting control valve (3) is in a neutral position, the second working oil port of the lifting control valve (3) is communicated with the oil return port of the lifting control valve (3); A steering control valve (4), wherein the oil inlet of the steering control valve (4) is connected to the first working oil port of the lifting control valve (3), the oil return port of the steering control valve (4) is connected to the oil tank (1), the first working oil port of the steering control valve (4) is connected to the rodless cavity of the steering actuator, the second working oil port of the steering control valve (4) is connected to the rod cavity of the steering actuator, and when the lifting control valve (3) is in the middle position, the first working oil port of the lifting control valve (3) is connected to the oil return port of the lifting control valve (3).

7. The hydraulic system for an aerial work platform according to claim 6, characterized in that: It also includes a first overflow valve (5), a first oil port of the first overflow valve (5) is connected to the first working oil port of the lift control valve (3) and the oil inlet of the steering control valve (4), and a second oil port of the first overflow valve (5) is connected to the oil tank (1).

8. The hydraulic system for an aerial work platform according to claim 1, characterized in that: The invention also includes a one-way valve (50), which is arranged on a pipeline between the oil outlet of the power device (2) and the oil inlet of the main control valve (30), and the one-way valve (50) is configured to conduct one-way flow from the power device (2) to the main control valve (30).

9. The hydraulic system for an aerial work platform according to claim 1, characterized in that: It also includes a main overflow valve (60), a first oil port of the main overflow valve (60) being connected to a pipeline between the oil outlet of the power device (2) and the oil inlet of the main control valve (30), and a second oil port of the main overflow valve (60) being connected to the oil tank (1).

10. Aerial work platform, characterized in that, A hydraulic system for an aerial work platform comprising any one of claims 1 to 9.

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